UFO enthusiasts claim to have spotted a massive alien spacecraft, around the size of the US state of Idaho, near the sun(NASA)

A recent image of the sun clicked by Nasa's Solar and Heliospheric Observatory (Soho) on 15 July 2015 has sparked rumours that a massive mothership is hovering around the hot star.

YouTube user Streetcap1 claims that the object that appears in the Nasa image is a gigantic alien spacecraft, around the size of the US state of Idaho.

"This object has structure and for Nasa to dismiss it as nothing is an insult to people's intelligence. If they post data then they must expect ufo hunters to find anomalies and share them," the UFO theorist said, describing the mysterious object in his YouTube video.

Aliens and UFOs have always fascinated humans, and conspiracy theories revolving around extraterrestrials, keep doing the rounds. UFO hunters also generate their own theories about anything suspicious in the sky and space seen through Nasa's live feed videos.

A close-up look at the alleged massive alien spacecraft spotted near the sun(NASA)

While many dismiss these theories as illusions, there are several others who believe there are living entities out there who visit earth to observe human life.

One such believer commenting in the YouTube video that aliens are evolved humans, said "They may be charging the craft with the energy near the sun."

Nasa has always refuted such rumours and has never endorsed theories about alien life visiting earth.

The space research organisation, however, is searching for life on planets other than earth with Kepler which has recently found an older cousin of the earth.

The Kepler mission has confirmed the first near-Earth-size planet in the "habitable zone" around a sun-like star.

"This exciting result brings us one step closer to finding an Earth 2.0. Kepler-452b is 60 percent larger in diameter than Earth and is considered a super-Earth-size planet. While its mass and composition are not yet determined, previous research suggests that planets the size of Kepler-452b have a good chance of being rocky," says Nasa.